At a packed Tower Theater on Saturday night, Yes' lead singer sounded and looked better than ever. His moves - hippy-dippy swayings punctuated by the occasional use of a finger cymbal - haven't changed. But he seemed younger, rejuvenated by the music - in this case the presentation of two classic Yes albums in their entirety, Fragile and Close to the Edge, both (amazingly) from 1972, when progressive rock was king.